/**
 * Copyright &copy; 2012-2016 <a href="http://www.vc-group.cn">vc-group</a> All rights reserved.
 */
package cn.vcjf.weapp.common.util;

import org.apache.shiro.session.Session;
import org.apache.shiro.session.mgt.eis.SessionIdGenerator;
import org.springframework.context.annotation.Lazy;
import org.springframework.stereotype.Service;

import java.io.Serializable;
import java.security.SecureRandom;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Random;
import java.util.UUID;

/**
 * 封装各种生成唯一性ID算法的工具类.
 * @author ThinkGem
 * @version 2013-01-15
 */
@Service
@Lazy(false)
public class IdGen implements SessionIdGenerator {

	private static SecureRandom random = new SecureRandom();
	private static String shortName="weapp";

	/**
	 * 封装JDK自带的UUID, 通过Random数字生成, 中间无-分割.
	 */
	public static String uuid() {
		return UUID.randomUUID().toString().replaceAll("-", "");
	}
	
	/**
	 * 使用SecureRandom随机生成Long. 
	 */
	public static long randomLong() {
		return Math.abs(random.nextLong());
	}

	/**
	 * 基于Base62编码的SecureRandom随机生成bytes.
	 */
	public static String randomBase62(int length) {
		byte[] randomBytes = new byte[length];
		random.nextBytes(randomBytes);
		return Encodes.encodeBase62(randomBytes);
	}

	/**
	 * 封装JDK自带的UUID, 通过Random数字生成, 中间无-分割.
	 */
	public static String getUnid() {
		return UUID.randomUUID().toString().replaceAll("-", "");
	}

	/**
	 * Activiti ID 生成
	 */
	public String getNextId() {
		return IdGen.uuid();
	}

	@Override
	public Serializable generateId(Session session) {
		return IdGen.uuid();
	}
	
	public static void main(String[] args) {
		long batchNo = Long.parseLong(new SimpleDateFormat("yyyyMMddHHmmssSSS").format(new Date()));
		System.out.println(batchNo);
//		System.out.println(IdGen.uuid());
//		System.out.println(IdGen.uuid().length());
//		System.out.println(new IdGen().getNextId());
//		for (int i=0; i<1000; i++){
//			System.out.println(IdGen.randomLong() + "  " + IdGen.randomBase62(5));
//		}
	}
	/**
	 * @param length 表示生成字符串的长度
	 * @return 随机字符
	 */
	public static String getRandomString(int length) {
		String base = "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
		Random random = new Random();
		StringBuffer sb = new StringBuffer();
		for (int i = 0; i < length; i++) {
			int number = random.nextInt(base.length());
			sb.append(base.charAt(number));
		}
		return sb.toString();
	}
	/**
	 * 获取时间戳
	 * @return
	 */
	public static String getDateString() {
		SimpleDateFormat sssdf = new SimpleDateFormat("yyyyMMddHHmmss");
		return sssdf.format(new Date());
	}
	/**
	 * 获取自动订单
	 * @return
	 */
	public static synchronized String getAutoOrderNo() {
		return shortName+ getDateString() + getRandomString(3);
	}
	/**
	 * 获取自动订单
	 * @return
	 */
	public static synchronized String getOrderNo() {
		return getDateString() + getRandomString(3);
	}
}
